Look up WikiData ID based using a Freebase ID. Possibly useful if you have lots of Freebase ids and want to turn them into WikiData ids when Freebase goes the way of the Dodo in June.

gistfile1.txt

% curl --silent 'https://wdq.wmflabs.org/api?q=string\[646:/m/04hcw\]' | python -mjson.tool
{
    "items": [
        9391
    ],
    "status": {
        "error": "OK",
        "items": 1,
        "parsed_query": "STRING[646:'/m/04hcw']",
        "querytime": "113ms"
    }
}